10 Best Tankless Hot Water Heaters 2026 in the United States

The Rinnai RXP199iN is a versatile tankless water heater designed for both indoor and outdoor use, thanks to its Versa Vent system. It runs on either natural gas or propane, which adds flexibility depending on your fuel preference. With a strong flow rate of up to 11.1 gallons per minute, it can supply hot water to around seven fixtures simultaneously, making it suitable for medium to large households. Its energy efficiency is excellent, boasting a UEF (Uniform Energy Factor) of 0.98, which means it uses fuel very efficiently and can help reduce energy bills.

The Rheem RTEX-24 Electric Tankless Water Heater is a solid choice for those seeking an efficient and high-capacity water heating solution. One of its major strengths is its impressive flow rate of up to 5.9 gallons per minute (GPM), which is suitable for serving multiple fixtures simultaneously. Additionally, its 99.8% energy efficiency rating makes it an economical option, as it minimizes energy waste and reduces utility bills.

The Rheem Natural Gas Condensing Tankless Water Heater offers a strong flow rate of up to 9 gallons per minute, suitable for households needing multiple hot water sources at once, such as showers and appliances running simultaneously. It operates on natural gas, which is often more cost-effective for home heating than electricity, and boasts a good energy efficiency rating of 0.93, helping reduce energy bills while providing continuous hot water. Its temperature settings range from 100 to 140°F, with a default of 120°F, allowing comfortable control over water temperature. The unit is compact, measuring about 18 by 24 inches, making it a good fit for indoor wall mounting without taking up much space. Installation requires venting due to the direct vent feature.